The present invention relates to a transmission equipment for transmitting frame through a network via a plurality of I/O physical ports as well as to a load-distribution transmitting method in the transmission equipment.
Conventionally, when a band required for frame transmission can not sufficiently be insured because of only one transfer path (physical port) provided between transmission equipments, there has been employed a method for providing a plurality of transfer paths between transmission equipments, dividing information thereinto, and transmitting the divided information; namely a load-distribution transmitting method. FIG. 49 is a block diagram showing configuration of a transmission equipment employing a load-distribution transmitting method based on the conventional technology. A transmission equipment 30 shown in FIG. 49 comprises frame receiving sections 31-0 to 31-10, frame transmitting sections 32-0 to 32-10, a switching section 33, a path deciding section 34, an output physical port deciding section 35, a load distribution table section 36, a load distribution table selecting section 37, an entry pointer table 38, and an entry pointer increment section 39.
Each of the frame receiving sections 31-0 to 31-10 receives a frame from a network connected thereto, and processes the received frame to a frame format in which the frame can be handled in the equipment. Each of those frame receiving sections 31-0 to 31-10 sends out a received frame to the switching section 33 respectively. Each of the frame transmitting sections 32-0 to 32-10 processes a transmitting frame to a format in which the transmitting frame can be outputted to a network connected thereto and sends the processed frame to the network. Here is shown an example of that 11 units of input physical port as well as of output physical port each at reference numerals #0 to #10 are provided in each of the frame transmitting sections.
The frame transmitting sections 32-0 to 32-7 correspond to output physical ports #0 to #7 respectively, and a bundle of the ports (grouping) is defined as a logical port #0. Also, the frame transmitting sections 32-8 and 32-9 correspond to output physical ports #8 and #9 respectively, and a bundle of the ports (grouping) is defined as a logical port #1. The frame transmitting section 32-10 corresponds to an output physical port #10, which is defined as a logical port #2.
The switching section 33 executes processing for switching to transmit a received frame from any frame receiving section having received the frame to any frame transmitting section corresponding to the output physical port number decided by the output physical port deciding section 35. The path deciding section 34 receives the received frame from the switching section 33, decides a path from the destination according to the received frame, and decides an output logical port corresponding to the path. This output logical port is used herein for defining a plurality of transfer paths which are discharging paths as a bundle thereof (grouping).
The output physical port deciding section 35 looks up any load distribution table selected from the load distribution table section 36 by the load distribution table selecting section 37 and decides an output physical port. The load distribution table section 36 is a group of tables in each of which one unit of load distribution table for controlling a correlation of an output physical port (zero unit, one unit or a plurality units) to an output logical port is allocated to each output logical port. Herein, load distribution tables 36-0 (#0) to 36-2 (#2) are prepared for the output logical ports #0 to #2 respectively.
The load distribution table selecting section 37 selects a load distribution table for deciding an output physical port from the load distribution table section 36 according to an output logical port number decided by the path deciding section 34. The entry pointer table 38 is a table in which an entry pointer for identifying a position of which load distribution table of the load distribution table section 36 is to be looked up is correlated to each of the load distribution tables 36-0 to 36-10 respectively.
The entry pointer increment section 39 increments, after any load distribution table is looked up, a current entry pointer in the entry pointer table 38 by one for looking up the load distribution table at the next time.
Next description is made for the operations. FIG. 50 is a simulated view for explaining a load-distribution transmitting method in the normal operation of the equipment according to the example based on the conventional, FIG. 51 is a view for explaining a method of changing an output physical port in the condition shown in FIG. 50, and FIG. 52 is a flow chart for explaining a sequence of load-distribution transmission according to the example based on the conventional technology.
FIG. 50 shows a grouping in the logical port #0 assuming that the transmission equipment 30 and a transmission equipment P as a partner connected thereto via a network are connected to each other with, for example, the same physical port numbers. Description is made hereinafter for a case where a frame is received in the physical port #0.
When a frame is received by the transmission equipment 30 (Frame receiving section 31-0: Physical port #0) from a network (step S61), the received frame is sent from the frame receiving section 31-0 to the path deciding section 34 via the switching section 33. It is assumed herein that the frame received from the network is transmitted by the transmission equipment 30 and transmitted to the transmission equipment P as a partner.
When the received frame is sent to the path deciding section 34, a destination is decided in the path deciding section 34 according to the destination information stored in the received frame, and a logical port number to which information for the received frame is to be outputted is decided according to the destination (step S62). The output logical port number decided by this path deciding section 34 is sent to the output physical port deciding section 35.
The output physical port deciding section 35 executes processing for supplying the output logical port number received from the path deciding section 34 to the load distribution table selecting section 37, and obtaining a load distribution table number to be selected as a response from the load distribution table selecting section 37. At this point of time, the load distribution table selecting section 37 selects, according to the received output logical port number, a load distribution table number corresponding thereto, and responds the load distribution table number to the output physical port deciding section 35.
When the load distribution table number is acquired by the output physical port deciding section 35 as described above, actual selection of the load distribution table is executed by the output physical port deciding section 35 (step S63). Namely, the load distribution table having the load distribution table number is accessed by the output physical port deciding section 35 through the load distribution table section 36. In this example, as a frame is received by the logical port #0, the load distribution table 36-0 (#0) is selected.
Then, in the output physical port deciding section 35, an entry pointer is looked up through the entry pointer table 38 (step S64), and a table entry to be looked up in the load distribution table is specified according to the entry pointer. The output physical port deciding section 35 decides an output physical port by looking up this specified table entry (step S65).
When the output physical port is decided as described above, a transmitting frame is sent out to the output physical port. In this case, as shown in FIG. 51, at first, #0 is decided as an output physical port number according to a first table entry, and for this reason, a first frame is transmitted from the frame transmitting section 32-0 corresponding to the output physical port #0 (step S66).
After the transmission, the entry pointer in the entry pointer table 38 is incremented by one by the entry pointer increment section 39 (step S67). When the frame is transmitted from the output physical port as described above, the processing for deciding the next output physical port is executed for load distribution. Namely, in FIG. 51, because the entry pointer has been incremented by one, the physical port #1 is decided in the same load distribution table 36-0 as the next output physical port according to the next table entry.
Similarly, the entry pointer is incremented each time when a frame is transmitted (output logical port #0), and a physical port is switched from #2 to #7 in association with the increment. It should be noted that, when the switching with the entry pointer reaches the last output physical port #7, the entry pointer returns to the initial value and specifies the output physical port #0.
As described above, in the frame transmission to the logical port #0, load-distribution transmission to received frames is realized using the physical ports #0 to #7. Also, if any frame is transmitted to the logical port #1, the load-distribution transmission similar to the case of the logical port #0 is realized using the physical ports #8 and #9, and if any frame is transmitted to the logical port #2, transmission with one output physical port which indicates no load distribution therein is realized using the physical port #10 (Refer to FIG. 51).
In the example based on the conventional technology, however, like the transmission equipment 30 shown in FIG. 49, when a received frame is to be transferred, an output physical port is decided by switching a load distribution table to be looked up, so that an look-up operation is needed for each frame transmission requiring load-distribution. For this reason, the load increases on the processing for load-distribution transmission, which may interfere with speed-up of frame transmitting.
Also, like the conventional type of transmission equipment shown in FIG. 49, in such configuration that one load distribution table is provided for each logical port, it is required to insure resources (hardware) constituting the load distribution table section 36, and for this reason, a scale of a circuit is larger as increase of the number of logical ports which is required for realizing rapid communications.
It is an object of the present invention, for solving the problems as described above, to provide a transmission equipment which can realize speed-up of a load-distribution transmission with compact circuit configuration not requiring look-up of a load distribution table as well as a load-distribution transmitting method in the transmission equipment.
To solve the problems as well as to achieve the object, a transmission equipment according to the present invention connected to a network for executing communications using a frame including destination information with a plurality of I/O physical ports for transmitting a frame transmission through the network via the plurality of I/O physical ports comprises an output logical port deciding unit for deciding an output logical port with an output physical port previously correlated thereto according to the destination information included, when a frame has been received from the network, in the received frame; an output physical port deciding unit for deciding an output physical port corresponding to the output logical port decided by the output logical port deciding unit; a frame transmitter for transmitting the received frame to the output physical port decided by the output physical port deciding unit; and an output physical port changing unit for changing any output physical port, of the plurality of output physical ports, decided by the output physical port deciding unit according to previously decided rules when received frames following the frame transmitted by the frame transmitter are successively transmitted.
With the transmission equipment according to the present invention, when received frames are to successively be transmitted, change of an output physical port is regularly executed within a plurality of output physical ports corresponding to an output logical port acquired from destination information. For this reason, it is possible to omit operations to look up a table each time when an output physical port with which a load is distributed is changed, so that speed-up of load-distribution transmission can be realized, and in addition, it is not required to insure resources constituting tables for the look-up, and for this reason, it is possible to realize a compact circuit for load-distribution transmission.
A transmission equipment according to the present invention connected to a network for executing communications using a frame including destination information with a plurality of I/O physical ports for transmitting a frame transmission through the network via the plurality of I/O physical ports comprises an output physical port table for storing therein variable output physical port numbers each for identifying any output physical port by corresponding to each of a plurality of previously decided output logical port numbers respectively and mask information for changing the variable output physical port number to distribute loads; an output logical port deciding unit for deciding an output logical port according to the destination information, when a frame has been received from the network, included in the received frame; an output physical port deciding unit for deciding an output physical port number corresponding to the output logical port number decided by the output logical port deciding unit by referring to the output physical port table; a frame transmitter for transmitting the received frame to the output physical port having an output physical port number decided by the output physical port deciding unit; and an output physical port changing unit for changing any output physical port number decided by the output physical port deciding unit according to the mask information correlated to the output logical port number decided by the output logical port deciding unit by referring to the output physical port table when received frames following the frame transmitted by the frame transmitter are successively transmitted.
With the transmission equipment according to the present invention, a plurality of output physical port numbers corresponding to the output logical port number acquired from destination information and mask information for varying any output physical port number of the plurality of output physical port numbers for load distribution are acquired by looking up an output physical port table, and when received frames are to successively be transmitted, change of an output physical port number is executed within a plurality of output physical port numbers corresponding to an output logical port acquired from the destination information. For this reason, it is possible to omit operations to look up a table each time when an output physical port with which a load is distributed is changed, so that speed-up of load-distribution transmission can be realized, and in addition, it is not required to insure resources constituting tables for the look-up, and for this reason, it is possible to realize a compact circuit for load-distribution transmission.
A transmission equipment according to the present invention connected to a network for executing communications using a frame including destination information with a plurality of I/O physical ports for transmitting a frame transmission through the network via the plurality of I/O physical ports comprises an output physical port table with one or a plurality of interface boards each correlated to each of a plurality of previously decided output logical ports provided therein, with a plurality of interface board-ports each provided in each of the interface boards, for deciding a number obtained by combining a board number for each of the interface boards with a corresponding number for a port in each of the plurality of interface boards as an output physical port number, and storing therein a variable output physical port number for identifying any output physical port by corresponding to each of the plurality of output logical port numbers and mask information for changing the variable output physical port number to distribute loads; an output logical port deciding unit for deciding an output logical port number according to the destination information, when a frame has been received from the network, included in the received frame; an output physical port deciding unit for deciding an output physical port number corresponding to the output logical port number decided by the output logical port deciding unit by referring to the output physical port table; a frame transmitter for transmitting the received frame to the output physical port having an output physical port number decided by the output physical port deciding unit; and an output physical port changing unit for changing any output physical port number decided by the output physical port deciding unit according to the mask information correlated to the output logical port number decided by the output logical port deciding unit by referring to the output physical port table when received frames following the frame transmitted by the frame transmitter are successively transmitted.
With the transmission equipment according to the present invention, a plurality of output physical port numbers (numbers each obtained by combining a board number for an interface board and a port number in a plurality of interface boards corresponding to the board number) corresponding to the output logical port number acquired from destination information and mask information for varying any output physical port number of the plurality of output physical port numbers for load distribution are acquired by looking up an output physical port table, and when received frames are to successively be transmitted, change of an output physical port number is executed according to the mask information within a plurality of output physical port numbers corresponding to the output logical port number acquired from the destination information. For this reason, even when a plurality of ports are provided in each of a plurality of interface boards respectively, it is possible to omit operations to look up a table each time when an output physical port with which a load is distributed is changed, so that speed-up of load-distribution transmission can be realized, and in addition, it is not required to insure resources constituting tables for the look-up, and for this reason, it is possible to realize a compact circuit for load-distribution transmission.
In a transmission equipment according to the present invention and also claimed in claim 2 or 3, the mask information defines a range for grouping a plurality of output physical port numbers, and the output physical port changing unit changes the output physical port number decided by the output physical port deciding unit within the range for grouping defined by the mask information.
With the transmission equipment according to the present invention, an output physical port number is changed within a range for grouping defined by the mask information, so that load-distribution transmission in an adequate band insured by the grouping can be realized.
In a transmission equipment according to the present invention, the output physical port changing unit changes output physical port numbers in ascending order or in descending order within the range for grouping.
With the transmission equipment according to the present invention, output physical port numbers are changed in ascending order or in descending order within the range for grouping, so that it is possible to acquire an output physical port number with regularity in changes within the range for grouping as well as a simple operational sequence.
In a transmission equipment according to the present invention, output physical port numbers and mask information stored in the output physical port table are numbers indicated in the same number of digits, and each of the mask information is information for identifying a digit position to be variable for the output physical port number correlated to the mask information.
With the transmission equipment according to the present invention, an output physical port number and mask information each comprise the same number of bits, and a digit position to be variable is specified with each of the mask information to a bit pattern of an output physical port number corresponding to the mask information, so that only an output physical port obtained by change of the digit position to be variable is used, and with this operation, it is possible to realize load-distribution transmission using any output physical port which is surely desired.
A transmission equipment according to the present invention further comprises an equipment-configuration defining detector for detecting change in definition concerning the equipment configuration for the equipment, and a mask information setting unit for changing and setting, when the definition concerning the equipment configuration for the equipment is changed by the equipment-configuration defining detector, mask information corresponding to each of the output logical ports to mask information for defining a range to insure a band for transfer paths adequate for changed contents of the definition concerning the equipment configuration from the range of grouping according to the mask information.
With the transmission equipment according to the present invention, the mask information corresponding to each of output logical ports is changed and set to mask information for defining a range to insure a band for a transfer path adequate for changed contents of the definition concerning the equipment configuration from the range of grouping according to the mask information, so that flexibility can be given to grouping according to the changed contents of the definition concerning the equipment configuration, and with this operation, the higher efficiency of load-distribution transmission can be achieved.
In a transmission equipment according to the present invention, the mask information setting unit enlarges or reduces the range of grouping so as to be a range for obtaining a band according to the changed conditions.
With the transmission equipment according to the present invention, the range of grouping is enlarged or reduced according to changed conditions of definition concerning the equipment configuration, so that a band to be insured can be enlarged or reduced according to enlargement or reduction of the grouping range, and with this operation, the higher efficiency of load-distribution transmission can be achieved.
A transmission equipment according to the present invention further comprises a communication trouble detector for detecting trouble over communications for each output physical port, and a mask information setting unit for changing and setting, when one or a plurality of output physical ports having trouble over communications are detected by the communication trouble detector, mask information corresponding to each of the output logical ports to mask information for defining a range in which the detected one or a plurality of output physical ports have been invalidated from the range of grouping according to the mask information.
With the transmission equipment according to the present invention, the mask information corresponding to each of the output logical ports is changed and set to mask information for defining a range in which one or a plurality of output physical ports each with communication trouble having been detected are invalidated from the range of grouping according to the mask information, so that any output physical port in which communication trouble occurs can be separated from others, and with this operation, communication trouble at the time of load-distribution transmission can securely be avoided.
A transmission equipment according to the present invention further comprises an overload detector for detecting an overloaded state in each output physical port, and a mask information setting unit for changing and setting, when one or a plurality of output physical ports each in an overloaded state are detected by the overload detector, mask information corresponding to each of the output logical ports to mask information for defining a range in which the detected one or a plurality of output physical ports have been invalidated from the range of grouping according to the mask information.
With the transmission equipment according to the present invention, the mask information corresponding to each of the output logical ports is changed and set to mask information for defining a range in which one or a plurality of output physical ports in which an overloaded state has been detected are invalidated from the range of grouping according to the mask information, so that any output physical port at the overloaded state can be separated from others, and with this operation, uniformity of a load at the time of load-distribution transmission can be achieved.
In a transmission equipment according to the present invention, the mask information setting unit changes mask information corresponding to each of the output logical ports to mask information for defining a range of grouping excluding digit positions therefrom corresponding to at least the detected one or a plurality of output physical ports.
With the transmission equipment according to the present invention, the mask information corresponding to each of the output logical ports is changed to mask information for defining a range of grouping excluding digit positions therefrom corresponding to at least one or a plurality of output physical ports in which any communication trouble has been detected, so that a grouping to which any output physical port having communication trouble does not belong can be acquired.
In a transmission equipment according to the present invention, the mask information setting unit changes mask information corresponding to each of the output logical ports to mask information for defining a range with digit positions obtained by moving from the digit positions corresponding to at least the detected one or a plurality of output physical ports as a range of grouping.
With the transmission equipment according to the present invention, the mask information corresponding to each of the output logical ports is changed to mask information for defining a range with digit positions obtained by moving from the digit positions corresponding to at least one or a plurality of output physical ports in which communication trouble has been detected as a range of grouping, so that a grouping not including any output physical port having communication trouble can be acquired.
In a transmission equipment according to the present invention, the communication trouble detector includes recovery from communication troubles in contents to detect thereby, and the mask information setting unit returns, when recovery from communication trouble is detected by the communication trouble detector, the mask information to the original mask information corresponding to each of the output logical ports.
With the transmission equipment according to the present invention, when recovery from communication trouble is detected, the mask information is returned to the original mask information corresponding to each of the output logical ports, so that a correlation between the output logical port and the mask information can be returned to the initial state before the communication trouble occurs, and with this operation, the system on the whole can automatically be recovered.
In a transmission equipment according to the present invention, the overload detector includes elimination of an overload in contents to detect thereby, and the mask information setting unit returns, when elimination of an overloaded state is detected by the overload detector, the mask information to the original mask information corresponding to each of the output logical ports.
With the transmission equipment according to the present invention, when elimination of an overloaded state is detected, the mask information is returned to the original mask information corresponding to each of the output logical ports, so that a correlation between the output logical port and the mask information can be returned to the initial state before the overload occurs, and with this operation, the system on the whole can automatically be recovered.
A load-distribution transmitting method in the transmission equipment according to the present invention connected to a network for executing communications using a frame including destination information with a plurality of I/O physical ports for transmitting a frame transmission through the network via the plurality of I/O physical ports comprises a first step of deciding an output logical port with an output physical port previously correlated thereto according to the destination information included, when a frame has been received from the network, in the received frame; a second step of deciding an output physical port corresponding to the output logical port decided in the first step; a third step of transmitting the received frame to the output physical port decided in the second step; and a fourth step of changing any output physical port, of the plurality of output physical ports, decided in the second step according to previously decided rules when received frames following the frame transmitted in the third step are successively transmitted.
With the load-distribution transmitting method in the transmission equipment according to the present invention, when received frames are to successively be transmitted, the method comprises a step of regularly executing change of an output physical port in a plurality of output physical ports each corresponding to the output logical port acquired from the destination information. For this reason, it is possible to omit operations to look up a table each time when an output physical port with which a load is distributed is changed, so that speed-up of load-distribution transmission can be realized, and in addition, it is not required to insure resources constituting tables for the look-up, and for this reason, it is possible to realize a compact circuit for load-distribution transmission.
Other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.